Poly(arylene ether)/polyamide composition and method of making

ABSTRACT

An composition comprises a poly(arylene ether), a polyamide, electrically conductive filler, an impact modifier, and a phosphinate. The composition may be used in a variety of articles such as furniture, partitions, containers, and vehicle interiors.

BACKGROUND OF INVENTION

Poly(arylene ether) resins have been blended with polyamide resins toprovide compositions having a wide variety of beneficial properties suchas heat resistance, chemical resistance, impact strength, hydrolyticstability and dimensional stability.

These beneficial properties are desirable in a wide variety ofapplications and the shapes and sizes of the parts required for theseapplications vary widely. As a result there is a variety of forming ormolding methods employed such as injection molding, compression moldingand extrusion. Each molding method requires a different set of physicalcharacteristics for the polymer being molded so a blend which issuitable for high shear/high pressure processes such as injectionmolding may not be suitable for low pressure/low shear processes such asblow molding, sheet extrusion and profile extrusion. For example,profile extrusion requires that a polymer blend be forced through ashaped die (a profile) and maintain the extruded shape until cooled. Theextruded shape may be further manipulated while the polymer blend isstill malleable through the use of shaping tools and the shaped profilemust retain its shape after manipulation. Therefore blends employed inlow pressure/low shear processes typically have fairly high meltviscosity (low melt flow indices) as well as high melt strength.

In some applications it is desirable that the extruded shape beelectrostatically coatable which requires use of an electricallyconductive material. Unfortunately the inclusion of electricallyconductive fillers in high melt viscosity blends can be problematic,particularly in a multi phase polymer blends such as a poly(aryleneether)/polyamide blend. Furthermore, flame retardancy of electricallyconductive high melt viscosity blends can be difficult to achieve.

BRIEF DESCRIPTION OF THE INVENTION

An composition comprising a poly(arylene ether), a polyamide,electrically conductive filler, an impact modifier, and a phosphinate.

DETAILED DESCRIPTION

As mentioned above low pressure/low shear molding processes requirematerials with a melt strength sufficiently high and a melt volume rate(MVR) sufficiently low to maintain the desired shape after leaving theextrusion die or mold. Additionally it is desirable for the materials tobe sufficiently electrically conductive to permit electrostatic coatingand have a flame retardancy rating of V-1 or better according toUnderwriter's Laboratory Bulletin 94 entitled “Tests for Flammability ofPlastic Materials, UL94” (UL94) at a thickness of 2.0 millimeters (mm).

A composition useful in low pressure/low shear molding processescomprises a poly(arylene ether), a polyamide, an impact modifier,electrically conductive filler, and a phosphinate. The melt volume rateof the composition is compatible with low pressure/low shear processes.In one embodiment the composition has a melt volume rate less than orequal to 25 cubic centimeters (cc)/10 min, or, more specifically, lessthan or equal to 20 cc/10 min, or, even more specifically, less than orequal to 16 cc/10 min, as determined by Melt Volume Rate test ISO 1133performed at 300° C. with a load of 5 kilograms (kg).

The composition may have a Vicat B120 greater than or equal to 170° C.,or, more specifically, greater than or equal to 180° C., or, even morespecifically, greater than or equal to 190° C. Vicat B120 is determinedusing ISO 306 standards. A Vicat B120 greater than or equal to 170° C.ensures that the composition has adequate heat performance forelectrostatic coating.

Specific volume resistivity (SVR) is a measure of the leakage currentdirectly through a material. It is defined as the electrical resistancethrough a one-centimeter cube of material and is expressed in ohm-cm.The lower the specific volume resistivity of a material, the moreconductive the material is. In one embodiment the composition has aspecific volume resistivity less than or equal to 106 ohm-cm, or, morespecifically, less than or equal to 10⁵, or, even more specifically,less than or equal to 10⁴. Specific volume resistivity may be determinedas described in the Examples. Surprisingly the inclusion of thephosphinate reduces the resistivity relative to a comparable compositionlacking phosphinate. As a result it is possible to achieve the same orlower resistivity in a composition comprising phosphinate andelectrically conductive filler than a composition comprisingelectrically conductive filler without phosphinate.

In some embodiments it may be advantageous for the composition to have avolatiles content sufficiently low to prevent or limit the amount ofbuild up on the molding equipment.

The terms “a” and “an” herein do not denote a limitation of quantity,but rather denote the presence of at least one of the referenced item.All ranges disclosed herein are inclusive and combinable (e.g., rangesof “less than or equal to 25 wt %, or, more specifically, 5 wt % to 20wt %,” is inclusive of the endpoints and all intermediate values of theranges of “5 wt % to 25 wt %,” etc.).

As used herein, a “poly(arylene ether)” comprises a plurality ofstructural units of the formula (I):

wherein for each structural unit, each Q¹ and each Q² is independentlyhydrogen, halogen, primary or secondary lower alkyl (e.g., an alkylcontaining 1 to 7 carbon atoms), phenyl, haloalkyl, aminoalkyl,alkenylalkyl, alkynylalkyl, aryl, hydrocarbonoxy, and halohydrocarbonoxywherein at least two carbon atoms separate the halogen and oxygen atoms.In some embodiments, each Q¹ is independently alkyl or phenyl, forexample, C₁₋₄ alkyl, and each Q² is independently hydrogen or methyl.The poly(arylene ether) may comprise molecules havingaminoalkyl-containing end group(s), typically located in an orthoposition to the hydroxy group. Also frequently present are tetramethyldiphenylquinone (TMDQ) end groups, typically obtained from reactionmixtures in which tetramethyl diphenylquinone by-product is present.

The poly(arylene ether) may be in the form of a homopolymer; acopolymer; a graft copolymer; an ionomer; a block copolymer, for examplecomprising arylene ether units and blocks derived from alkenyl aromaticcompounds; as well as combinations comprising at least one of theforegoing. Poly(arylene ether) includes polyphenylene ether containing2,6-dimethyl-1,4-phenylene ether units optionally in combination with2,3,6-trimethyl-1,4-phenylene ether units.

The poly(arylene ether) may be prepared by the oxidative coupling ofmonohydroxyaromatic compound(s) such as 2,6-xylenol and/or2,3,6-trimethylphenol. Catalyst systems are generally employed for suchcoupling; they can contain heavy metal compound(s) such as a copper,manganese or cobalt compound, usually in combination with various othermaterials such as a secondary amine, tertiary amine, halide orcombination of two or more of the foregoing.

The poly(arylene ether) can have a number average molecular weight of3,000 to 40,000 grams per mole (g/mol) and/or a weight average molecularweight of about 5,000 to about 80,000 g/mol, as determined by gelpermeation chromatography using monodisperse polystyrene standards, astyrene divinyl benzene gel at 40° C. and samples having a concentrationof 1 milligram per milliliter of chloroform. The poly(arylene ether) canhave an intrinsic viscosity of 0.10 to 0.60 deciliters per gram (dl/g),or, more specifically, 0.29 to 0.48 dl/g, as measured in chloroform at25° C. It is possible to utilize a combination of high intrinsicviscosity poly(arylene ether) and a low intrinsic viscosity poly(aryleneether). Determining an exact ratio, when two intrinsic viscosities areused, will depend somewhat on the exact intrinsic viscosities of thepoly(arylene ether) used and the ultimate physical properties that aredesired.

In one embodiment the poly(arylene ether) has a glass transitiontemperature (Tg) as determined by differential scanning calorimetry (DSCat 20° C./minute ramp), of 160° C. to 250° C. Within this range the Tgmay be greater than or equal to 180° C., or, more specifically, greaterthan or equal to 200° C. Also within this range the Tg may be less thanor equal to 240° C., or, more specifically, less than or equal to 230°C.

The composition comprises poly(arylene ether) in an amount of 15 to 65weight percent. Within this range, the poly(arylene ether) may bepresent in an amount greater than or equal to 30 weight percent, or,more specifically, in an amount greater than or equal to 35 weightpercent, or, even more specifically, in an amount greater than or equalto 40 weight percent. Also within this range the poly(arylene ether) maybe present in an amount less than or equal to 60 weight percent, or,more specifically, less than or equal to 55 weight percent, or, evenmore specifically, less than or equal to 50 weight percent. Weightpercent is based on the total weight of the thermoplastic composition.

Polyamide resins, also known as nylons, are characterized by thepresence of an amide group (—C(O)NH—), and are described in U.S. Pat.No. 4,970,272. Exemplary polyamide resins include, but are not limitedto, nylon-6; nylon-6,6; nylon-4; nylon-4,6; nylon-12; nylon-6,10; nylon6,9; nylon-6,12; amorphous polyamide resins; nylon 6/6T and nylon 6,6/6Twith triamine contents below 0.5 weight percent; and combinations of twoor more of the foregoing polyamides. In one embodiment, the polyamideresin comprises nylon 6 and nylon 6,6. In one embodiment the polyamideresin or combination of polyamide resins has a melting point (Tm)greater than or equal to 171° C. When the polyamide comprises a supertough polyamide, i.e. a rubber-toughed polyamide, the composition may ormay not contain a separate impact modifier.

Polyamide resins may be obtained by a number of well known processessuch as those described in U.S. Pat. Nos. 2,071,250; 2,071,251;2,130,523; 2,130,948; 2,241,322; 2,312,966; and 2,512,606. Polyamideresins are commercially available from a wide variety of sources.

Polyamide resins having an intrinsic viscosity of up to 400 millilitersper gram (ml/g) can be used, or, more specifically, having a viscosityof 90 to 350 ml/g, or, even more specifically, having a viscosity of 110to 240 ml/g, as measured in a 0.5 wt % solution in 96 wt % sulfuric acidin accordance with ISO 307.

The polyamide may have a relative viscosity of up to 6, or, morespecifically, a relative viscosity of 1.89 to 5.43, or, even morespecifically, a relative viscosity of 2.16 to 3.93. Relative viscosityis determined according to DIN 53727 in a 1 wt % solution in 96 wt %sulfuric acid.

In one embodiment, the polyamide resin comprises a polyamide having anamine end group concentration greater than or equal to 35microequivalents amine end group per gram of polyamide (μeq/g) asdetermined by titration with HCl. Within this range, the amine end groupconcentration may be greater than or equal to 40 μeq/g, or, morespecifically, greater than or equal to 45 μeq/g. Amine end group contentmay be determined by dissolving the polyamide in a suitable solvent,optionally with heat. The polyamide solution is titrated with 0.01Normal hydrochloric acid (HCl) solution using a suitable indicationmethod. The amount of amine end groups is calculated based the volume ofHCl solution added to the sample, the volume of HCl used for the blank,the molarity of the HCl solution and the weight of the polyamide sample.

In one embodiment, the polyamide comprises greater than or equal to 50weight percent, based on the total weight of the polyamide, of apolyamide having a melt temperature within 35%, or more specificallywithin 25%, or, even more specifically, within 15% of the glasstransition temperature (Tg) of the poly(arylene ether). As used hereinhaving a melt temperature within 35% of the glass transition temperatureof the polyarylene ether is defined as having a melt temperature that isgreater than or equal to (0.65×Tg of the poly(arylene ether)) and lessthan or equal to (1.35×Tg of the poly(arylene ether)).

The composition comprises polyamide in an amount of 30 to 85 weightpercent. Within this range, the polyamide may be present in an amountgreater than or equal to 33 weight percent, or, more specifically, in anamount greater than or equal to 38 weight percent, or, even morespecifically, in an amount greater than or equal to 40 weight percent.Also within this range, the polyamide may be present in an amount lessthan or equal to 60 weight percent, or, more specifically, less than orequal to 55 weight percent, or, even more specifically, less than orequal to 50 weight percent. Weight percent is based on the total weightof the thermoplastic composition

When used herein, the expression “compatibilizing agent” refers topolyfunctional compounds which interact with the poly(arylene ether),the polyamide resin, or both. This interaction may be chemical (e.g.,grafting) and/or physical (e.g., affecting the surface characteristicsof the dispersed phases). In either instance the resultingcompatibilized poly(arylene ether)/polyamide composition appears toexhibit improved compatibility, particularly as evidenced by enhancedimpact strength, mold knit line strength and/or elongation. As usedherein, the expression “compatibilized poly(arylene ether)/polyamideblend” refers to those compositions which have been physically and/orchemically compatibilized with an agent as discussed above, as well asthose compositions which are physically compatible without such agents,as taught in U.S. Pat. No. 3,379,792.

Examples of the various compatibilizing agents that may be employedinclude: liquid diene polymers, epoxy compounds, oxidized polyolefinwax, quinones, organosilane compounds, polyfunctional compounds,functionalized poly(arylene ether) and combinations comprising at leastone of the foregoing. Compatibilizing agents are further described inU.S. Pat. Nos. 5,132,365 and 6,593,411 as well as U.S. PatentApplication No. 2003/0166762.

In one embodiment, the compatibilizing agent comprises a polyfunctionalcompound. Polyfunctional compounds which may be employed as acompatibilizing agent are of three types. The first type ofpolyfunctional compounds are those having in the molecule both (a) acarbon-carbon double bond or a carbon-carbon triple bond and (b) atleast one carboxylic acid, anhydride, amide, ester, imide, amino, epoxy,orthoester, or hydroxy group. Examples of such polyfunctional compoundsinclude maleic acid; maleic anhydride; fumaric acid; glycidyl acrylate,itaconic acid; aconitic acid; maleimide; maleic hydrazide; reactionproducts resulting from a diamine and maleic anhydride, maleic acid,fumaric acid, etc.; dichloro maleic anhydride; maleic acid amide;unsaturated dicarboxylic acids (e.g., acrylic acid, butenoic acid,methacrylic acid, t-ethylacrylic acid, pentenoic acid); decenoic acids,undecenoic acids, dodecenoic acids, linoleic acid, etc.); esters, acidamides or anhydrides of the foregoing unsaturated carboxylic acids;unsaturated alcohols (e.g. alkyl alcohol, crotyl alcohol, methyl vinylcarbinol, 4-pentene-1-ol, 1,4-hexadiene-3-ol, 3-butene-1,4-diol,2,5-dimethyl-3-hexene-2,5-diol and alcohols of the formulaC_(n)H_(2n-5)OH, C_(n)H_(2n-7)OH and C_(n)H_(2n-9)OH, wherein n is apositive integer less than or equal to 30); unsaturated amines resultingfrom replacing from replacing the —OH group(s) of the above unsaturatedalcohols with NH₂ groups; functionalized diene polymers and copolymers;and combinations comprising one or more of the foregoing. In oneembodiment, the compatibilizing agent comprises maleic anhydride and/orfumaric acid.

The second type of polyfunctional compatibilizing agents arecharacterized as having both (a) a group represented by the formula (OR)wherein R is hydrogen or an alkyl, aryl, acyl or carbonyl dioxy groupand (b) at least two groups each of which may be the same or differentselected from carboxylic acid, acid halide, anhydride, acid halideanhydride, ester, orthoester, amide, imido, amino, and various saltsthereof. Typical of this group of compatibilizers are the aliphaticpolycarboxylic acids, acid esters and acid amides represented by theformula:(R^(I)O)_(m)R(COOR^(II))_(n)(CONR^(III)R^(IV))_(s)wherein R is a linear or branched chain, saturated aliphatic hydrocarbonhaving 2 to 20, or, more specifically, 2 to 10, carbon atoms; R^(I) ishydrogen or an alkyl, aryl, acyl, or carbonyl dioxy group having 1 to10, or, more specifically, 1 to 6, or, even more specifically, 1 to 4carbon atoms; each R^(II) is independently hydrogen or an alkyl or arylgroup having 1 to 20, or, more specifically, 1 to 10 carbon atoms; eachR^(III) and R^(IV) are independently hydrogen or an alkyl or aryl grouphaving 1 to 10, or, more specifically, 1 to 6, or, even morespecifically, 1 to 4, carbon atoms; m is equal to 1 and (n+s) is greaterthan or equal to 2, or, more specifically, equal to 2 or 3, and n and sare each greater than or equal to zero and wherein (OR^(I)) is alpha orbeta to a carbonyl group and at least two carbonyl groups are separatedby 2 to 6 carbon atoms. Obviously, R^(I), R^(II), R^(III), and R^(IV)cannot be aryl when the respective substituent has less than 6 carbonatoms.

Suitable polycarboxylic acids include, for example, citric acid, malicacid, agaricic acid; including the various commercial forms thereof,such as for example, the anhydrous and hydrated acids; and combinationscomprising one or more of the foregoing. In one embodiment, thecompatibilizing agent comprises citric acid. Illustrative of estersuseful herein include, for example, acetyl citrate, mono- and/ordistearyl citrates, and the like. Suitable amides useful herein include,for example, N,N′-diethyl citric acid amide; N-phenyl citric acid amide;N-dodecyl citric acid amide; N,N′-didodecyl citric acid amide; andN-dodecyl malic acid. Derivates include the salts thereof, including thesalts with amines and the alkali and alkaline metal salts. Exemplary ofsuitable salts include calcium malate, calcium citrate, potassiummalate, and potassium citrate.

The third type of polyfunctional compatibilizing agents arecharacterized as having in the molecule both (a) an acid halide groupand (b) at least one carboxylic acid, anhydride, ester, epoxy,orthoester, or amide group, preferably a carboxylic acid or anhydridegroup. Examples of compatibilizers within this group include trimelliticanhydride acid chloride, chloroformyl succinic anhydride, chloro formylsuccinic acid, chloroformyl glutaric anhydride, chloroformyl glutaricacid, chloroacetyl succinic anhydride, chloroacetylsuccinic acid,trimellitic acid chloride, and chloroacetyl glutaric acid. In oneembodiment, the compatibilizing agent comprises trimellitic anhydrideacid chloride.

The foregoing compatibilizing agents may be added directly to the meltblend or pre-reacted with either or both of the poly(arylene ether) andpolyamide, as well as with other resinous materials employed in thepreparation of the composition. With many of the foregoingcompatibilizing agents, particularly the polyfunctional compounds, evengreater improvement in compatibility is found when at least a portion ofthe compatibilizing agent is pre-reacted, either in the melt or in asolution of a suitable solvent, with all or a part of the poly(aryleneether). It is believed that such pre-reacting may cause thecompatibilizing agent to react with the polymer and, consequently,functionalize the poly(arylene ether). For example, the poly(aryleneether) may be pre-reacted with maleic anhydride to form an anhydridefunctionalized polyphenylene ether which has improved compatibility withthe polyamide compared to a non-functionalized polyphenylene ether.

Where the compatibilizing agent is employed in the preparation of thecompositions, the amount used will be dependent upon the specificcompatibilizing agent chosen and the specific polymeric system to whichit is added.

Impact modifiers can be block copolymers containing alkenyl aromaticrepeating units, for example, A-B diblock copolymers and A-B-A triblockcopolymers having of one or two alkenyl aromatic blocks A (blocks havingalkenyl aromatic repeating units), which are typically styrene blocks,and a rubber block, B, which is typically an isoprene or butadieneblock. The butadiene block may be partially or completely hydrogenated.Mixtures of these diblock and triblock copolymers may also be used aswell as mixtures of non-hydrogenated copolymers, partially hydrogenatedcopolymers, fully hydrogenated copolymers and combinations of two ormore of the foregoing.

A-B and A-B-A copolymers include, but are not limited to,polystyrene-polybutadiene, polystyrene-poly(ethylene-propylene),polystyrene-polyisoprene, poly(α-methylstyrene)-polybutadiene,polystyrene-polybutadiene-polystyrene (SBS),polystyrene-poly(ethylene-propylene)-polystyrene,polystyrene-polyisoprene-polystyrene andpoly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene),polystyrene-poly(ethylene-propylene-styrene)-polystyrene, and the like.Mixtures of the aforementioned block copolymers are also useful. SuchA-B and A-B-A block copolymers are available commercially from a numberof sources, including Phillips Petroleum under the trademark SOLPRENE,Kraton Polymers, under the trademark KRATON, Dexco under the trademarkVECTOR, Asahi Kasai under the trademark TUFTEC, Total Petrochemicalsunder the trademarks FINAPRENE and FINACLEAR and Kuraray under thetrademark SEPTON.

In one embodiment, the impact modifier comprisespolystyrene-poly(ethylene-butylene)-polystyrene,polystyrene-poly(ethylene-propylene) or a combination of the foregoing.

Another type of impact modifier is essentially free of alkenyl aromaticrepeating units and comprises one or more moieties selected from thegroup consisting of carboxylic acid, anhydride, epoxy, oxazoline, andorthoester. Essentially free is defined as having alkenyl aromatic unitapresent in an amount less than 5 weight percent, or, more specifically,less than 3 weight percent, or, even more specifically less than 2weight percent, based on the total weight of the block copolymer. Whenthe impact modifier comprises a carboxylic acid moiety the carboxylicacid moiety may be neutralized with an ion, preferably a metal ion suchas zinc or sodium. It may be an alkylene-alkyl (meth)acrylate copolymerand the alkylene groups may have 2 to 6 carbon atoms and the alkyl groupof the alkyl (meth)acrylate may have 1 to 8 carbon atoms. This type ofpolymer can be prepared by copolymerizing an olefin, for example,ethylene and propylene, with various (meth)acrylate monomers and/orvarious maleic-based monomers. The term (meth)acrylate refers to boththe acrylate as well as the corresponding methacrylate analogue.Included within the term (meth)acrylate monomers are alkyl(meth)acrylate monomers as well as various (meth)acrylate monomerscontaining at least one of the aforementioned reactive moieties.

In a one embodiment, the copolymer is derived from ethylene, propylene,or mixtures of ethylene and propylene, as the alkylene component; butylacrylate, hexyl acrylate, or propyl acrylate as well as thecorresponding alkyl (methyl)acrylates, for the alkyl (meth)acrylatemonomer component, with acrylic acid, maleic anhydride, glycidylmethacrylate or a combination thereof as monomers providing theadditional reactive moieties (i.e., carboxylic acid, anhydride, epoxy).

Exemplary first impact modifiers are commercially available from avariety of sources including ELVALOY PTW, SURLYN, and FUSABOND, all ofwhich are available from DuPont.

The aforementioned impact modifiers can be used singly or incombination.

The composition may comprise an impact modifier or a combination ofimpact modifiers, in an amount of 1 to 15 weight percent. Within thisrange, the impact modifier may be present in an amount greater than orequal to 1.5 weight percent, or, more specifically, in an amount greaterthan or equal to 2 weight percent, or, even more specifically, in anamount greater than or equal to 4 weight percent. Also within thisrange, the impact modifier may be present in an amount less than orequal to 13 weight percent, or, more specifically, less than or equal to12 weight percent, or, even more specifically, less than or equal to 10weight percent. Weight percent is based on the total weight of thethermoplastic composition.

The electrically conductive filler may comprise electrically conductivecarbon black, carbon nanotubes, carbon fibers or a combination of two orore of the foregoing. Electrically conductive carbon blacks arecommercially available and are sold under a variety of trade names,including but not limited to S.C.F. (Super Conductive Furnace), E.C.F.(Electric Conductive Furnace), Ketjen Black EC (available from Akzo Co.,Ltd.) or acetylene black. In some embodiments the electricallyconductive carbon black has an average particle size less than or equalto 200 nanometers (nm), or, more specifically, less than or equal to 100nm, or, even more specifically, less than or equal to 50 mm. Theelectrically conductive carbon blacks may also have surface areasgreater than 200 square meter per gram (m²/g), or, more specifically,greater than 400 m²/g, or, even more specifically, greater than 1000m²/g. The electrically conductive carbon black may have a pore volumegreater than or equal to 40 cubic centimeters per hundred grams (cm³/100g), or, more specifically, greater than or equal to 100 cm³/100 g, or,even more specifically, greater than or equal to 150 cm³/100 g, asdetermined by dibutyl phthalate absorption.

Carbon nanotubes that can be used include single wall carbon nanotubes(SWNTs), multiwall carbon nanotubes (MWNTs), vapor grown carbon fibers(VGCF) and combinations comprising two or more of the foregoing.

Single wall carbon nanotubes (SWNTs) may be produced bylaser-evaporation of graphite, carbon arc synthesis or a high-pressurecarbon monoxide conversion process (HIPCO) process. These SWNTsgenerally have a single wall comprising a graphene sheet with outerdiameters of 0.7 to 2.4 nanometers (nm). The SWNTs may comprise amixture of metallic SWNTs and semi-conducting SWNTs. Metallic SWNTs arethose that display electrical characteristics similar to metals, whilethe semi-conducting SWNTs are those that are electricallysemi-conducting. In some embodiments it is desirable to have thecomposition comprise as large a fraction of metallic SWNTs as possible.SWNTs may have aspect ratios of greater than or equal to 5, or, morespecifically, greater than or equal to 100, or, even more specifically,greater than or equal to 1000. While the SWNTs are generally closedstructures having hemispherical caps at each end of the respectivetubes, it is envisioned that SWNTs having a single open end or both openends may also be used. The SWNTs generally comprise a central portion,which is hollow, but may be filled with amorphous carbon.

In one embodiment the SWNTs comprise metallic nanotubes in an amount ofgreater than or equal to 1 wt %, or, more specifically, greater than orequal to 20 wt %, or, more specifically, greater than or equal to 30 wt%, or, even more specifically greater than or equal to 50 wt %, or, evenmore specifically, greater than or equal to 99.9 wt % of the totalweight of the SWNTs.

In one embodiment the SWNTs comprise semi-conducting nanotubes in anamount of greater than or equal to 1 wt %, or, more specifically,greater than or equal to 20 wt %, or, more specifically, greater than orequal to 30 wt %, or, even more specifically, greater than or equal to50 wt %, or, even more specifically, greater than or equal to 99.9 wt %of the total weight of the SWNTs.

MWNTs may be produced by processes such as laser ablation and carbon arcsynthesis. MWNTs have at least two graphene layers bound around an innerhollow core. Hemispherical caps generally close both ends of the MWNTs,but it is also possible to use MWNTs having only one hemispherical capor MWNTs which are devoid of both caps. MWNTs generally have diametersof 2 to 50 nm. Within this range, the MWNTs may have an average diameterless than or equal to 40, or, more specifically, less than or equal to30, or, even more specifically less than or equal to 20 nm. MWNTs mayhave an average aspect ratio greater than or equal to 5, or, morespecifically, greater than or equal to 100, or, even more specificallygreater than or equal to 1000.

Vapor grown carbon fibers (VGCF) are generally manufactured in achemical vapor deposition process. VGCF having “tree-ring” or “fishbone”structures may be grown from hydrocarbons in the vapor phase, in thepresence of particulate metal catalysts at moderate temperatures, i.e.,800 to 1500° C. In the “tree-ring” structure a multiplicity ofsubstantially graphitic sheets are coaxially arranged about the core. Inthe “fishbone” structure, the fibers are characterized by graphitelayers extending from the axis of the hollow core.

VGCF having diameters of 3.5 to 2000 nanometers (nm) and aspect ratiosgreater than or equal to 5 may be used. VGCF may have diameters of 3.5to 500 nm, or, more specifically 3.5 to 100 nm, or, even morespecifically 3.5 to 50 nm. VGCF may have an average aspect ratiosgreater than or equal to 100, or, more specifically, greater than orequal to 1000.

Various types of conductive carbon fibers may also be used in thecomposition. Carbon fibers are generally classified according to theirdiameter, morphology, and degree of graphitization (morphology anddegree of graphitization being interrelated). These characteristics arepresently determined by the method used to synthesize the carbon fiber.For example, carbon fibers having diameters down to 5 micrometers, andgraphene ribbons parallel to the fiber axis (in radial, planar, orcircumferential arrangements) are produced commercially by pyrolysis oforganic precursors in fibrous form, including phenolics,polyacrylonitrile (PAN), or pitch.

The carbon fibers generally have a diameter of greater than or equal to1,000 nanometers (1 micrometer) to 30 micrometers. Within this rangefibers having sizes of greater than or equal to 2, or, morespecifically, greater than or equal to 3, or, more specifically greaterthan or equal to 4 micrometers may be used. Also within this rangefibers having diameters of less than or equal to 25, or, morespecifically, less than or equal to 15, or, even more specifically lessthan or equal to 11 micrometers may be used.

The composition comprises a sufficient amount of electrically conductivefiller to achieve a specific volume resistivity less than or equal to10⁶ ohm-cm. For example, the composition may comprise electricallyconductive carbon black and/or carbon fibers and/or carbon nanotubes inan amount of 1 to 20 weight percent. Within this range, the electricallyconductive filler may be present in an amount greater than or equal to1.2 weight percent, or, more specifically, in an amount greater than orequal to 1.4 weight percent, or, even more specifically, in an amountgreater than or equal to 1.6 weight percent. Also within this range, theelectrically conductive carbon filler may be present in an amount lessthan or equal to 15 weight percent, or, more specifically, less than orequal to 10 weight percent, or, even more specifically, less than orequal to 5 weight percent. Weight percent is based on the total weightof the thermoplastic composition.

In some embodiments it is desirable to incorporate a sufficient amountof electrically conductive filler to achieve a specific volumeresistivity that is sufficient to permit the composition to dissipateelectrostatic charges or to be thermally dissipative.

The phosphinate may comprise one or more phosphinates of formula II,III, or IV

wherein R¹ and R² are independently C₁-C₆ alkyl, phenyl, or aryl; R³ isindependently C₁-C₁₀ alkylene, C₆-C₁₀ arylene, C₆-C₁₀ alkylarylene, orC₆-C₁₀ arylalkylene; M is calcium, magnesium, aluminum, zinc or acombination comprising one or more of the foregoing; d is 2 or 3; f is 1or 3; x is 1 or 2; each R⁴ and R⁵ are independently a hydrogen group ora vinyl group of the formula —CR⁷═CHR⁸; R⁷ and R⁸ are independentlyhydrogen, carboxyl, carboxylic acid derivative, C₁-C₁₀ alkyl, phenyl,benzyl, or an aromatic substituted with a C₁-C₈ alkyl; K isindependently hydrogen or a 1/r metal of valency r and u, the averagenumber of monomer units, may have a value of 1 to 20.

Examples of R¹ and R² include, but are not limited to, methyl, ethyl,n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, and phenyl. Examplesof R³ include, but are not limited to, methylene, ethylene, n-propylene,isopropylene, n-butylene, tert-butylene, n-pentylene, n-octylene,n-dodecylene, phenylene, naphthylene, methylphenylene, ethylphenylene,tert-butylphenylene, methylnapthylene, ethylnapthylene,tert-butylnaphthylene, phenylethylene, phenylpropylene, andphenylbutylene.

The mono- and diphosphinates (formulas II and III respectively) may beprepared by reacting the corresponding phosphinic acid with a metaloxide and/or metal hydroxide in an aqueous medium as taught in EP 0 699708.

The polymeric phosphinates (formula IV) may be prepared by reactinghypophosphorous acid and or its alkali metal salt with an acetylene offormula (V)R⁷—C≡C—R⁸  (V).The resulting polymeric phosphinic acid or polymeric phosphinic acidsalt is then reacted with a metal compound of groups IA, IIA, IIIA, IVA,VA, IIB, IVB, VIIB, VIIIB of the Periodic Table as taught in U.S. PatentApplication No. 2003/0216533.

In one embodiment, R¹ and R² are ethyl.

In one embodiment the phosphinate is in particulate form. Thephosphinate particles may have a median particle diameter (D50) lessthan or equal to 40 micrometers, or, more specifically, a D50 less thanor equal to 30 micrometers, or, even more specifically, a D50 less thanor equal to 25 micrometers. Additionally, the phosphinate may becombined with a polymer, such as a poly(arylene ether), a polyolefin, apolyamide, and/or an impact modifier, to form a masterbatch. Thephosphinate masterbatch comprises the phosphinate in an amount greaterthan is present in the thermoplastic composition. Employing amasterbatch for the addition of the phosphinate to the other componentsof the composition can facilitate addition and improve distribution ofthe phosphinate.

The composition comprises an amount of phosphinate sufficient to achievea flame retardance of V-1 or better at a thickness of 2.0 millimetersaccording to UL94. In one embodiment the composition comprises an amountof phosphinate sufficient to achieve a flame retardance of V-0 at athickness of 2.0 millimeters according to UL94. For example, thecomposition may comprise phosphinate in an amount of 5 to 25 weightpercent. Within this range, the phosphinate may be present in an amountgreater than or equal to 7 weight percent, or, more specifically, in anamount greater than or equal to 8 weight percent, or, even morespecifically, in an amount greater than or equal to 9 weight percent.Also within this range the phosphinate may be present in an amount lessthan or equal to 22 weight percent, or, more specifically, less than orequal to 17 weight percent, or, even more specifically, less than orequal to 15 weight percent. Weight percent is based on the total weightof the thermoplastic composition.

The composition may optionally comprise an inorganic compound such as anoxygen compound of silicon, a magnesium compound, a metal carbonate ofmetals of the second main group of the periodic table, red phosphorus, azinc compound, an aluminum compound or a composition comprising one ormore of the foregoing. The oxygen compounds of silicon can be salts oresters of orthosilicic acid and condensation products thereof;silicates; zeolites; silicas; glass powders; glass-ceramic powders;ceramic powders; or combinations comprising one or more of the foregoingoxygen compound of silicon. The magnesium compounds can be magnesiumhydroxide, hydrotalcites, magnesium carbonates or magnesium calciumcarbonates or a combination comprising one or more of the foregoingmagnesium compounds. The red phosphorus can be elemental red phosphorusor a preparation in which the surface of the phosphorus has been coatedwith low-molecular-weight liquid substances, such as silicone oil,paraffin oil or esters of phthalic acid or adipic acid, or withpolymeric or oligomeric compounds, e.g., with phenolic resins or aminoplastics, or else with polyurethanes. The zinc compounds can be zincoxide, zinc stannate, zinc hydroxystannate, zinc phosphate, zinc borate,zinc sulfides or a composition comprising one of more of the foregoingzinc compounds. The aluminum compounds can be aluminum hydroxide,aluminum phosphate, or a combination thereof.

In one embodiment, the inorganic compound comprises zinc borate.

The composition may optionally comprise a nitrogen compound orcombination of nitrogen compounds. Exemplary nitrogen compounds includethose having the formulas (VI) to (XI):

wherein R⁹ to R¹¹ are independently hydrogen; C₁-C₈-alkyl;C₅-C₁₆-cycloalkyl unsubstituted or substituted with a hydroxyl functionor with a C₁-C₄-hydroxyalkyl function; C₅-C₁₆-alkylcycloalkyl,unsubstituted or substituted with a hydroxyl function or with aC₁-C₄-hydroxyalkyl function; C₂-C₈-alkenyl; C₂-C₈-alkoxy; C₂-C₈-acyl;C₂-C₈-acyloxy; C₆-C₁₂-aryl; C₆-C₁₂-arylalkyl; —OR²⁰; —N(R²⁰)R¹²;N-alicyclic; N-aromatic systems;

R²⁰ is hydrogen; C₁-C₈-alkyl; C₅-C₁₆-cycloalkyl, unsubstituted orsubstituted with a hydroxyl function or with a C₁-C₄-hydroxyalkylfunction; C₅-C₁₆-alkylcycloalkyl, unsubstituted or substituted with ahydroxyl function or with a C¹-C₄-hydroxyalkyl function; C₂-C₈-alkenyl;C¹-C₈-alkoxy; C₁-C₈-acyl; C₁-C₈-acyloxy; C₆-C₁₂-aryl; orC₆-C₁₂-arylalkyl;

R¹² to R¹⁶ are groups identical with R²⁰ or else —O—R²⁰,

g and h, independently of one another, are 1, 2, 3 or 4,

G is the residue of an acid which can form an adduct with triazinecompounds (VI). The nitrogen compound may also be an ester oftris(hydroxyethyl) isocyanurate with aromatic polycarboxylic acids, anitrogen-containing phosphate of the formula (NH₄)_(y)H_(3-y)PO₄ or(NH₄PO₃)_(z), where y is from 1 to 3 and z is from 1 to 10,000 or acombination comprising one or more of the foregoing nitrogen compounds.

Exemplary nitrogen compounds include melamine polyphosphate, melemphosphate, melam phosphate, melamine pyrophosphate, melamine, melaminecyanurate, combinations comprising one or more of the foregoing, and thelike.

The composition can be prepared melt mixing or a combination of dryblending and melt mixing. Melt mixing can be performed in single or twinscrew type extruders or similar mixing devices which can apply a shearto the components.

All of the ingredients may be added initially to the processing system.In some embodiments, the poly(arylene ether) may be precompounded withthe compatibilizing agent. Additionally other ingredients such as animpact modifier, phosphinate, optional synthetic inorganic compound,optional nitrogen compound, and a portion of the polyamide may beprecompounded with the compatibilizing agent and poly(arylene ether). Inone embodiment, the poly(arylene ether) is precompounded with thecompatibilizing agent to form a functionalized poly(arylene ether). Thefunctionalized poly(arylene ether) is then compounded with the otheringredients. In another embodiment the poly(arylene ether),compatibilizing agent, impact modifier, phosphinate, optional syntheticinorganic compound, and optional nitrogen compound are compounded toform a first material and the polyamide is then compounded with thefirst material. The phosphinate, optional synthetic inorganic compoundand optional nitrogen compound may be added to the poly(arylene ether)as a masterbatch. The phosphinate, optional synthetic inorganic compoundand optional nitrogen compound may be added to the polyamide as amasterbatch.

When using an extruder, all or part of the polyamide may be fed througha port downstream. While separate extruders may be used in theprocessing, preparations in a single extruder having multiple feed portsalong its length to accommodate the addition of the various componentssimplifies the process. It is often advantageous to apply a vacuum tothe melt through one or more vent ports in the extruder to removevolatile impurities in the composition.

The electrically conductive filler may be added by itself, with otheringredients (optionally as a dry blend) or as part of a masterbatch. Inone embodiment, the electrically conductive filler can be part of amasterbatch comprising polyamide. The electrically conductive filler maybe added with the poly(arylene ether), with the polyamide (the secondportion when two portions are employed), or after the addition of thepolyamide (the second portion when two portions are employed).

In one embodiment the composition comprises the reaction product ofpoly(arylene ether); polyamide; electrically conductive filler;compatibilizing agent; impact modifier; and phosphinate. As used hereina reaction product is defined as the product resulting from the reactionof two or more of the foregoing components under the conditions employedto form the composition, for example during compounding or high shearmixing.

After the composition is formed it is typically formed into strandswhich are cut to form pellets. The strand diameter and the pellet lengthare typically chosen to prevent or reduce the production of fines(particles that have a volume less than or equal to 50% of the pellet)and for maximum efficiency in subsequent processing such as profileextrusion. An exemplary pellet length is 1 to 5 millimeters and anexemplary pellet diameter is 1 to 5 millimeters.

The pellets may exhibit hygroscopic properties. Once water is absorbedit may be difficult to remove. Typically drying is employed but extendeddrying can affect the performance of the composition. Similarly water,above 0.01-0.1%, or, more specifically, 0.02-0.07% moisture by weight,can hinder the use of the composition in some applications. It isadvantageous to protect the composition from ambient moisture. In oneembodiment the pellets, once cooled to a temperature of 50° C. to 110°C., are packaged in a container comprising a mono-layer of polypropyleneresin free of a metal layer wherein the container has a wall thicknessof 0.25 millimeters to 0.60 millimeters. The pellets, once cooled to 50to 110° C. can also be packaged in foiled lined containers such as foillined boxes and foil lined bags.

The composition may be converted to articles using low shearthermoplastic processes such as film and sheet extrusion, profileextrusion, extrusion molding, compression molding and blow molding. Filmand sheet extrusion processes may include and are not limited to meltcasting, blown film extrusion and calendaring. Co-extrusion andlamination processes may be employed to form composite multi-layer filmsor sheets. Single or multiple layers of coatings may further be appliedto the single or multi-layer substrates to impart additional propertiessuch as scratch resistance, ultra violet light resistance, aestheticappeal, etc. Coatings may be applied through standard applicationtechniques such as rolling, spraying, dipping, brushing, orflow-coating.

Oriented films may be prepared through blown film extrusion or bystretching cast or calendared films in the vicinity of the thermaldeformation temperature using conventional stretching techniques. Forinstance, a radial stretching pantograph may be employed for multi-axialsimultaneous stretching; an x-y direction stretching pantograph can beused to simultaneously or sequentially stretch in the planar x-ydirections. Equipment with sequential uniaxial stretching sections canalso be used to achieve uniaxial and biaxial stretching, such as amachine equipped with a section of differential speed rolls forstretching in the machine direction and a tenter frame section forstretching in the transverse direction.

The compositions may be converted to multiwall sheet comprising a firstsheet having a first side and a second side, wherein the first sheetcomprises a thermoplastic polymer, and wherein the first side of thefirst sheet is disposed upon a first side of a plurality of ribs; and asecond sheet having a first side and a second side, wherein the secondsheet comprises a thermoplastic polymer, wherein the first side of thesecond sheet is disposed upon a second side of the plurality of ribs,and wherein the first side of the plurality of ribs is opposed to thesecond side of the plurality of ribs.

The films and sheets described above may further be thermoplasticallyprocessed into shaped articles via forming and molding processesincluding but not limited to thermoforming, vacuum forming, pressureforming, injection molding and compression molding. Multi-layered shapedarticles may also be formed by injection molding a thermoplastic resinonto a single or multi-layer film or sheet substrate as described below:

-   -   1. Providing a single or multi-layer thermoplastic substrate        having optionally one or more colors on the surface, for        instance, using screen printing or a transfer dye    -   2. Conforming the substrate to a mold configuration such as by        forming and trimming a substrate into a three dimensional shape        and fitting the substrate into a mold having a surface which        matches the three dimensional shape of the substrate.    -   3. Injecting a thermoplastic resin into the mold cavity behind        the substrate to (i) produce a one-piece permanently bonded        three-dimensional product or (ii) transfer a pattern or        aesthetic effect from a printed substrate to the injected resin        and remove the printed substrate, thus imparting the aesthetic        effect to the molded resin.

Those skilled in the art will also appreciate that common curing andsurface modification processes including and not limited toheat-setting, texturing, embossing, corona treatment, flame treatment,plasma treatment and vacuum deposition may further be applied to theabove articles to alter surface appearances and impart additionalfunctionalities to the articles.

Accordingly, another embodiment relates to articles, sheets and filmsprepared from the compositions above.

Exemplary articles include all or portions of the following articles:furniture, partitions, containers, vehicle interiors including railcars, subway cars, busses, trolley cars, airplanes, automobiles, andrecreational vehicles, exterior vehicle accessories such as roof rails,appliances, cookware, electronics, analytical equipment, window frames,wire conduit, flooring, infant furniture and equipment,telecommunications equipment, antistatic packaging for electronicsequipment and parts, health care articles such as hospital beds anddentist chairs, exercise equipment, motor covers, display covers,business equipment parts and covers, light covers, signage, air handlingequipment and covers, automotive underhood parts.

The following non-limiting examples further illustrate the variousembodiments described herein.

EXAMPLES

The following examples used the materials shown in Table 1. Weightpercent, as used in the examples, is determined based on the totalweight of the composition unless otherwise noted. TABLE 1 Material NameMaterial Description/Supplier PPE A poly(2,6-dimethylphenylene ether)with an intrinsic viscosity of 0.46 dl/g as measured in chloroform at25° C. commercially available from General Electric SEBSPolystyrene-poly(ethylene-butylene)-polystyrene commercially availableas Kraton 1651 from Kraton Polymers Nylon 6,6 Polyamide having a 2.66ml/g relative viscosity determined according to DIN 53727 (1.0 wt %solution in 96 wt % sulfuric acid)and commercially available fromSolutia under the tradename Vydyne 21Z. Nylon 6#1 Polyamide having arelative viscosity of 2.40 determined according to DIN 53727 (1.0 wt %solution in 96 wt % sulfuric acid) and commercially available fromRhodia under the tradename Technyl HSN 27/32-35 LC Natural. Nylon 6 #2Polyamide having a relative viscosity of 2.85 determined according toDIN 53727 (1.0 wt % solution in 96 wt % sulfuric acid) and commerciallyavailable from Custom Resins under the tradename Nylene NX4512. 1312 Amixture of components comprising a phosphinate available commerciallyfrom Clariant corporation under the tradename Exolit OP 1312 CCBElectrically conductive carbon black commercially available from Akzounder the tradename Ketjen Black EC600JD. RDP Resorcinol diphosphate TPPTriphenyl phosphate MC Melamine cyanurate BP Boron phosphate SF Siliconefluid commercially available from GE Silicones under the tradenameSF1706.

Examples 1-7 and Comparative Examples 1-11

PPE, 0.1 weight percent (wt %) potassium iodide, 0.05 wt % copperiodide, 0.3 wt % Irganox 1076 commercially available from Ciba-Geigy,0.6 wt % citric acid, and the nylon 6,6 were melt mixed to form amixture. The mixture was further melt mixed with nylon 6 and amasterbatch of electrically conductive carbon black in nylon 6. Incompositions containing Exolit OP 1312, SF, BP, TPP, RDP, MC or acombination of two or more of the foregoing, these materials were addedwith the polyphenylene ether at the feedthroat. The compositions weremolded into bars having a thickness of 2.0 millimeters for flammabilitytesting. Flammability tests were performed following the procedure ofUnderwriter's Laboratory Bulletin 94 entitled “Tests for Flammability ofPlastic Materials, UL94”. Each bar that extinguished was ignited twice.According to this procedure, the materials were classified as either HB,V0, V1 or V2 on the basis of the test results obtained for ten samples.If more than 3 of the first 5 bars had a burn time >30 seconds, then theburning was stopped at 5 bars. The criteria for each of theseflammability classifications according to UL94, are, briefly, asfollows.

HB: In a 5 inch sample, placed so that the long axis of the sample isparallel to the flame, the rate of burn of the sample is less than 3inches per minute, and the flames should be extinguished before 4 inchesof sample are burned.

V0: In a sample placed so that its long axis is parallel to the flame,the average period of flaming and/or smoldering after removing theigniting flame should not exceed five seconds and none of the verticallyplaced samples should produce drips of burning particles which igniteabsorbent cotton.

V1: In a sample placed so that its long axis is parallel to the flame,the average period of flaming and/or smoldering after removing theigniting flame should not exceed twenty-five seconds and none of thevertically placed samples should produce drips of burning particleswhich ignite absorbent cotton.

V2: In a sample placed so that its long axis is parallel to the flame,the average period of flaming and/or smoldering after removing theigniting flame should not exceed twenty-five seconds and the verticallyplaced samples produce drips of burning particles which ignite cotton.

Results are shown in Table 2. Flame out time (FOT) is the average of thesum of the amounts of time the bar burned each time it was lit. “NA” inthe UL94 rating column means that the sample did not fall within theparameters of any of the UL94 ratings.

Some examples were tested for specific volume resistivity (SVR). Thecompositions were molded into ISO tensile bars. The bars were scored andthen submerged in liquid nitrogen for approximately 5 minutes. As soonas the bars were removed from the liquid nitrogen they were snapped atthe score marks. The ends were painted with electrically conductivesilver paint and dried. Resistance was measured by placing the probes ofa handheld multimeter on each painted end of the bar. The resistivitywas calculated as the resistance (in Ohms)×bar width (in centimeters(cm))×bar depth (cm) divided by the bar length (cm). Results are shownin Table 2. Comparative examples are noted as CE and examples are Ex.

Melt Volume rate was determined according to ISO 1133. Vicat B wasdetermined according to ISO 306. TABLE 2 CE 1 CE 2 CE 3 CE 4 CE 5 CE 6Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Component PPE 49.90 42.64 42.64 42.6447.21 49.00 44.34 48.0 42.0 42.0 42.95 SEBS 4.27 4.07 4.07 4.07 4.04 4.03.86 6.0 6.0 2.0 6.0 Nylon 66 11.5 10.94 10.94 10.94 10.88 11.29 9.868.0 12.0 8.0 8.0 Nylon 6 #1 — — — — — 22.98 29.35 27.0 27.0 33.0 27.0Nylon 6 #2 33.06 31.46 31.46 31.46 31.28 9.49 — — — — — CCB — — — — —2.0 2.0 2.2 1.8 2.2 1.8 1312 — — — — — — 9.34 7.55 9.95 11.55 13.0 RDP —— 9.68 — — — — — — — — TPP — — — 9.68 — — — — — — — MC — 9.68 — — — — —— — — — BP — — — — 3.27 — — — — — — SF — — — — 2.12 — — — — — — Physicalproperties Melt — — — — — 9.0 5.9 10.8 12.6 9.8 Volume Rate Vicat B — —— — — — 194 183 186 194 181 SVR — — — — — — 299 204 641 142 386 Avg. FOT100+ 100+ 100+ 23.5 18.8 100+ 4.8 3.9 3.9 3.9 3.9 UL94 NA NA NA NearNear NA V0 V0 V0 V0 V0 V1 V1 Ex. 6 Ex. 7 CE 7 CE 8 CE 9 CE 10 CE 11Component PPE 48.0 42.0 43.74 40.21 39.61 39.61 48.95 SEBS 2.0 6.0 3.973.92 3.96 3.96 4.2 Nylon 66 8.0 12.0 11.22 11.07 11.18 11.18 11.3 Nylon6 #1 27.0 27.0 22.84 22.53 22.75 22.75 32.5 Nylon 6 #2 — — 9.43 9.3 9.49.4 — CCB 1.8 1.8 1.99 1.96 1.98 1.98 1.8 1312 11.95 9.95 — — — — — RDP— — — — 9.89 — — TPP — — — — — 9.89 — MC — — — 9.79 — — — BP — — 3.38 —— — — SF — — 2.18 — — — — Physical properties Melt 10.4 10.8 — — — —10.2 Volume Rate Vicat B 195 186 — — — — 198 SVR 284 641 — — — — 23832Avg. FOT 4.2 3.9 49.8 100+ 100+ 45.9 100+ UL94 V0 V0 NA NA NA NA NA

Comparative Examples 1-5 demonstrate flame retardance behavior ofseveral blends that do not contain electrically conductive carbon black.Comparative Example 1 shows a generic compatibilizedpolyamide/poly(arylene ether) blend. No flame retarding additives werepresent. The flame retardance is poor, with an average flame out time(FOT) per bar greater than 100 seconds. Other well known flameretardants were added in similar loadings in Comparative Examples 2through 5. Comparative Example 2 with melamine cyanurate and ComparativeExample 3 with resorcinol diphosphate both had average FOT greater than100 seconds. Comparative Example 4, with triphenylphosphate, had anaverage FOT of 23.5 seconds, which begins to approach V-1 performance.However several of the individual burn times were longer than 30 secondsand therefore the material received no rating. Finally, a combination ofboron phosphate and silicone fluid (Comparative Example 5) produced asample with an average FOT of 18.8 seconds. This sample also was veryclose to but did not meet V-1 criteria in that one burn time was longerthan 30 seconds.

Comparative Examples 6-11 demonstrate the flame retardance behavior ofseveral blends that contain electrically conductive carbon black.Comparative Example 6 is an example of a electrically conductivecompatibilized polyamide/poly(arylene ether) blend without flameretardants. As can be seen, the flame retardancy is very poor with anaverage FOT greater than 100 seconds per bar. Comparative Example 7includes the same boron phosphate/silicone fluid flame retardant systemas in Comparative Example 5. Here the average FOT per bar is now 48.8seconds where without the electrically conductive carbon black, it was18.8 seconds. This shows that the inclusion of the electricallyconductive carbon black actually decreases the overall flame retardanceperformance of the blend. Similarly Comparative Example 10 uses TPP asthe flame retardance agent. This blend can be compared to ComparativeExample 4. With the electrically conductive carbon black in the blend,the average FOT per bar increases from 23.5 seconds to 45.9 seconds.

Examples 1 through 7 show blends that contain a phosphinate. All threesamples for each of these examples show a total average FOT below 5seconds per bar, even including from 1.8 to 2.2 parts of electricallyconductive carbon black. So, use of a phosphinate provides V-0performance in the electrically conductive blends. This is contrast tothe flame retardants used in the comparative examples that all showednon-V-0 performance with the addition of the electrically conductivecarbon black to the blends.

Additionally, a comparison of the specific volume resistivity ofComparative Example 11 (approximately 24000 Ohm-cm) to the specificvolume resistivity of Examples 1 through 7 shows that similar blendsthat have the same level of carbon black, but which also includephosphinate exhibit markedly lower resistivity. In all of Examples 1through 7, the resistivity decreases by at least 97%. So, the inclusionof phosphinate also unexpectedly reduces the resistivity, or increasesthe conductivity, of the compatibilized poly(arylene ether)/polyamideblends.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

1. A composition comprising: a poly(arylene ether); a polyamide; anelectrically conductive filler; an impact modifier; and a phosphinate.2. The composition of claim 1 wherein the composition has a melt volumerate less than or equal to 25 cubic centimeters/10 min as determined byMelt Volume Rate test ISO 1133 performed at 300° C. with a load of 5kilograms (kg).
 3. The composition of claim 2 wherein the compositionhas a melt volume rate less than or equal to 20 cubic centimeters/10 minas determined by Melt Volume Rate test ISO 1133 performed at 300° C.with a load of 5 kilograms (kg).
 4. The composition of claim 2 whereinthe composition has a melt volume rate less than or equal to 16 cubiccentimeters/10 min, as determined by Melt Volume Rate test ISO 1133performed at 300° C. with a load of 5 kilograms (kg).
 5. The compositionof claim 1 wherein the composition has a Vicat B 120 greater than orequal to 170° C. as determined by ISO
 306. 6. The composition of claim 1wherein the composition has a Vicat B120 greater than or equal to 180°C. as determined by ISO
 306. 7. The composition of claim 1 wherein thecomposition has a Vicat B120 greater than or equal to 190° C. asdetermined by ISO
 306. 8. The composition of claim 1, wherein thecomposition has a specific volume resistivity less than or equal to 10⁶ohm-cm.
 9. The composition of claim 1, wherein the composition has aspecific volume resistivity less than or equal to 10⁵ ohm-cm.
 10. Thecomposition of claim 1, wherein the poly(arylene ether) has a glasstransition temperature of 160° C. to 250° C.
 11. The composition ofclaim 1, wherein the poly(arylene ether) has a glass transitiontemperature of 200° C. to 230° C.
 12. The composition of claim 1 whereinthe poly(arylene ether) is present in an amount of 15 to 60 weightpercent, based on the total weight of the composition.
 13. Thecomposition of claim 1, wherein the polyamide has an intrinsic viscosityof 90 to 350 ml/g as measured in a 0.5 wt % solution in 96 wt % sulfuricacid in accordance with ISO
 307. 14. The composition of claim 1, whereinthe polyamide has a relative viscosity of 1.89 to 5.43 as measuredaccording to DIN 53727 in a 1 wt % solution in 96 wt % sulfuric acid.15. The composition of claim 1 wherein the polyamide comprises apolyamide having an amine end group concentration greater than or equalto 35 microequivalents per gram.
 16. The composition of claim 1 whereingreater than or equal to 50 weight percent of the polyamide, based onthe total weight of the polyamide, has a melt temperature within 35% ofthe glass transition temperature of the poly(arylene ether).
 17. Thecomposition of claim 1 wherein greater than or equal to 50 weightpercent of the polyamide, based on the total weight of the polyamide,has a melt temperature within 25% of the glass transition temperature ofthe poly(arylene ether).
 18. The composition of claim 1 wherein greaterthan or equal to 50 weight percent of the polyamide, based on the totalweight of the polyamide, has a melt temperature within 15% of the glasstransition temperature of the poly(arylene ether).
 19. The compositionof claim 1 wherein the polyamide is present in an amount of 30 to 85weight percent, based on the total weight of the composition.
 20. Thecomposition of claim 1 wherein the poly(arylene ether) and polyamide arecompatibilized.
 21. The composition of claim 1 wherein the impactmodifier comprises polystyrene-poly(ethylene-butylene)-polystyrene,polystyrene-poly(ethylene-propylene) or a combination of the foregoing.22. The composition of claim 1 wherein the impact modifier is present inan amount of 1 to 15 weight percent, based on the total weight of thecomposition.
 23. The composition of claim 1 wherein the electricallyconductive filler comprises electrically conductive carbon black, carbonnanotubes, carbon fibers or a combination of the two or more of theforegoing.
 24. The composition of claim 1 wherein the phosphinate hasthe formula

wherein R¹ and R² are independently C₁-C₆ alkyl, phenyl, or aryl; M iscalcium, magnesium, aluminum, zinc or a combination comprising one ormore of the foregoing; and d is 2 or
 3. 25. The composition of claim 24wherein R¹ and R² are ethyl.
 26. The composition of claim 1 furthercomprising a synthetic inorganic compound.
 27. The composition of claim17, wherein the synthetic inorganic compound comprises zinc borate. 28.The composition of claim 1, wherein the composition further comprises anitrogen compound.
 29. The composition of claim 1, wherein thecomposition has a V-1 rating or better according to UL94.
 30. Acomposition comprising the reaction product of a poly(arylene ether); apolyamide; a electrically conductive filler; a compatibilizing agent; animpact modifier; and a phosphinate.
 31. A method of making a compositioncomprising melt mixing a mixture comprising a poly(arylene ether), animpact modifier, a phosphinate, and a compatibilizing agent to form afirst blend; melt mixing the first blend with a polyamide and aelectrically conductive filler to form a composition.
 32. An articlecomprising a composition comprising a poly(arylene ether); a polyamide;a electrically conductive filler; a compatibilizing agent; an impactmodifier; and a phosphinate.
 33. The article of claim 32 wherein thearticle is thermally dissipative.